MULTISCALE FRET SLOTTING
GMC Luthier Tools offer a range of pre-designed Multiscale Templates & Jigs. The jig greatly simplifies the process of creating a multiscale fretboard. The range is based on common specifications of jigs previously supplied to customer requirements.
In addition to our standard jigs, we can provide custom jigs and templates to your requirements. Recent supply includes extra wide multiscale jigs for 10-string guitars.
STANDARD MULTISCALE FRET SLOTTING JIG
The jig includes everything needed for making a multiscale fretboard:
Fretboard Template & 2 Fret Slot Locators.
Slotting Jig Base.
Geometry Layout Gauge.
JIG SETUP / FRETBOARD PREPARATION
The fretboard is located between the jig side plates. The jig base has a grooved rubber surface which supports the fretboard and provides grip.
The template is a specially manufactured channel that fits over the outside of the jig base and rests directly on the top of the fretboard. The template is fastened via screws along the sides of the jig base and its height can be adjusted to suit the fretboard thickness.
To react against the cutting stroke and avoid fretboard movement when cutting the slots, the fretboard blank should be trimmed for a snug fit inside the jig base side plates - (78mm). Narrower boards can be used with some improvisation e.g. by adding some thin packers at the jig edges. As all geometry relates to the centre of the jig, it is essential that the board is not pushed to one side when cutting.
The fret slot locators should be fitted after cutting initial slots at opposite ends of the board - ideally positioned at the 1st fret and last fret. These maintain alignment of the fretboard and template.
The jig is robust enough to be clamped in a vice for use. If there is excess board length then supplementary clamping over the top of the jig using soft clamps can be employed at the ends - subject to the particular template design and available space outside of the fret slots. Care with positioning and type of clamps will be required to avoid damage or distortion to the template.
The template has a centreline reference at each end. Prior to cutting the slots or before removing from the jig, the centre of the fretboard should be marked as it will be an essential reference for building the instrument.
A precision luthiers fretsaw with hardwood handle and 5x 32tpi blades is included. Kerf Width 0.023" / 0.6mm.
The blades are easily changed. The saw body is purpose designed with an internal backstop for blade support and efficient cutting.
The blade is guided in the template slots and the saw teeth pass through notches at the sides of the template. Fret slot depth is achieved when the fretsaw back contacts the top surface of the template. The fretsaw supplied – 4.5mm depth – includes an allowance for the template thickness.
MULTISCALE GEOMETRY LAYOUT GAUGE:
The gauge provides the geometry and relationships with reference to the centre line of the instrument as follows:
Treble Scale Length
Bass Scale Length
Nut String Spacing (Overall)
Bridge String Spacing (Overall)
The Layout Gauge is a valuable reference tool for the instrument build.
JIG BASE DIMENSIONS
The multiscale jig base is 715mm long and will accommodate 78mm maximum fretboard width. The jig base also accepts our standard slotting jig templates for conventional guitar, baritone and bass scales.
SPECIALIST BRIDGE & SADDLE SUPPLIERS
Multiscale bridges and individual saddles are available from specialist suppliers and these can offer a convenient option/solution for your bridge requirement.
Q. The bridge I would like to use has a slightly different spacing to the templates that you have. Can the jig still be used for this.?
A. Yes. If the overall string spacing on the bridge differs, then this can be accommodated on the instrument by adjusting the overall nut spacing pro rata (same % factor - not measurement). This will ensure that strings still intersect all frets at correct theoretical points.
Q. Can the jig be used for different numbers of strings?.
A. Yes. Any adjustments made to the overall bridge spacing must be made pro rata (%) to the nut. (The actual scale lengths for bass and treble will change slightly - this is dependent on the amount of change in string spacing).